J/AJ/155/226 Gemini Planet Imager spectra of HR 8799 c/d/e (Greenbaum+, 2018)
GPI spectra of HR 8799 c, d and e from 1.5 to 2.4 µm with KLIP forward
modeling.
Greenbaum A.Z., Pueyo L., Ruffio J.-B., Wang J.J., De Rosa R.J.,
Aguilar J., Rameau J., Barman T., Marois C., Marley M.S., Konopacky Q.,
Rajan A., Macintosh B., Ansdell M., Arriaga P., Bailey V.P., Bulger J.,
Burrows A.S., Chilcote J., Cotten T., Doyon R., Duchene G.,
Fitzgerald M.P., Follette K.B., Gerard B., Goodsell S.J., Graham J.R.,
Hibon P., Hung L.-W., Ingraham P., Kalas P., Larkin J.E., Maire J.,
Marchis F., Metchev S., Millar-Blanchaer M.A., Nielsen E.L., Norton A.,
Oppenheimer R., Palmer D., Patience J., Perrin M.D., Poyneer L.,
Rantakyro F.T., Savransky D., Schneider A.C., Sivaramakrishnan A., Song I.,
Soummer R., Thomas S., Wallace J.K., Ward-Duong K., Wiktorowicz S.,
Wolff S.
<Astron. J., 155, 226-226 (2018)>
=2018AJ....155..226G 2018AJ....155..226G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Exoplanets ; Spectra, infrared
Keywords: planets and satellites: gaseous planets - stars: individual: HR 8799
Abstract:
We explore Karhunen Loeve Image Projection (KLIP) forward modeling spectral
extraction on Gemini Planet Imager coronagraphic data of HR 8799, using
PyKLIP, and show algorithm stability with varying KLIP parameters. We
report new and re-reduced spectrophotometry of HR 8799 c, d, and e in
the H and K bands. We discuss a strategy for choosing optimal KLIP PSF
subtraction parameters by injecting simulated sources and recovering them
over a range of parameters. The K1/K2 spectra for HR 8799 c and d are
similar to previously published results from the same data set. We also
present a K-band spectrum of HR 8799 e for the first time and show that
our H-band spectra agree well with previously published spectra from
the VLT/SPHERE instrument. We show that HR 8799 c and d show significant
differences in their H and K spectra, but do not find any conclusive
differences between d and e, nor between c and e, likely due to large error
bars in the recovered spectrum of e. Compared to M-, L-, and T-type field
brown dwarfs, all three planets are most consistent with mid- and late-L
spectral types. All objects are consistent with low gravity, but a lack
of standard spectra for low gravity limit the ability to fit the best
spectral type. We discuss how dedicated modeling efforts can better fit
HR 8799 planets' near-IR flux, as well as how differences between the
properties of these planets can be further explored.
Description:
HR 8799 was observed with the GPI Integral Field Spectrograph (IFS)
(Macintosh et al. 2014PNAS..11112661M 2014PNAS..11112661M), using its K1 and K2 filters,
on 2013 November 17 (median seeing 0.97") and November 18 (median seeing
0.75 arcsec), respectively, during GPI's first light. The data were
acquired with a continuous field-of-view (FOV) rotation near the meridian
transit to achieve maximum FOV rotation suitable for ADI processing
(Marois et al. 2006ApJ...641..556M 2006ApJ...641..556M). Conditions are described in detail
in Ingraham et al. (2014ApJ...794L..15I 2014ApJ...794L..15I). During the last 10 exposures of
the K1 observations, cryocooler power was decreased to 30% to reduce
vibration, and the last 14 exposures of the K2 observations had the
cryocooler power decreased. Since commissioning, linear-quadratic-Gaussian
control has been implemented (Poyneer et al. 2016ApOpt..55..323P 2016ApOpt..55..323P) and the
cryocooling system has been upgraded with active dampers to mitigate
cryocooler cycle vibrations. HR 8799 was observed again on 2016
September 19 in GPI's H band (median seeing 0.97"), as a part of the GPI
Expolanet Survey with the updated active damping system. Planet b falls
outside the FOV in these data.
Objects:
-------------------------------------------------
RA (ICRS) DE Designation(s)
-------------------------------------------------
23 07 28.72 +21 08 03.3 HR 8799 = HD 218396
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 95 111 GPI spectrum of the HR 8799 c, d, and e,
in flux units at 10 pc
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See also:
J/ApJ/761/57 : CHARA array angular diameters of HR 8799 (Baines+, 2012)
J/A+A/587/A57 : HR 8799e and HR 8799d spectra (Zurlo+, 2016)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 F7.5 um lambda(c) [1.50776/2.36972] Wavelength for HR 8799 c
9- 19 E11.6 W/m2/um Flux(c) [1.12703e-15/3.20672e-15] Flux for HR 8799 c
21- 31 E11.6 W/m2/um e_Flux(c) [7.93267e-17/1.36498e-15] Uncertainty in
Flux(c)
33- 39 F7.5 um lambda(d) [1.50776/2.36972] Wavelength for HR 8799 d
41- 51 E11.6 W/m2/um Flux(d) [1.33467e-15/3.28311e-15] Flux for HR 8799 d
53- 63 E11.6 W/m2/um e_Flux(d) [9.62034e-17/1.4416e-15] Uncertainty in
Flux(d)
65- 71 F7.5 um lambda(e) [1.50776/2.36972] Wavelength for HR 8799 e
73- 83 E11.6 W/m2/um Flux(e) [1.00613e-15/4.61147e-15]? Flux for
HR 8799 e
85- 95 E11.6 W/m2/um e_Flux(e) [3.08768e-16/2.22156e-15]? Uncertainty in
Flux(e)
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 14-Dec-2018